According to a Dow Jones Newswires report, Gates told Microsoft software partners in South Africa this week that the operating system could be delayed yet again if beta testers turn up problems.

The current schedule from Microsoft has the operating system being released to corporate customers later this year, with mainstream launch in January.

Gates said the company was spending $8 billion to $9 billion to develop Vista and the next version of Office, Dow Jones reported. Gates said he hopes the next version of Office will be ready in December.